The slow thaw
19 Mar 2014 by hddbqtthcb.d hddbqtthcb.d
Despite the headline-making recent insights, some maintain the Universe didn’t start with the Big Bang; instead it thawed from an extremely cold and almost static state.
Professor Christof Wetterich has developed a theoretical model that he says complements the conventional model of cosmic expansion and describes the same observations and physical reality as the Big Bang model, but removes the idea of singularity.
Singularity suggests that the closer we get to the Big Bang, the stronger the geometry of space and time curves until it becomes infinitely large. Shortly after the Big Bang, the universe was incredibly hot and dense.
However, Wetterich proposes that the birth of the universe stretches into the infinite past, and suggests the masses of the elementary particles increase and the gravitational constant decreases with cosmic time, while Newtonian attraction remains unchanged. This would have allowed for a very cold, slow start to the universe.
“There is no longer a singularity in this new picture of the cosmos,” said Wetterich, from Heidelberg University’s Institute for Theoretical Physics.
The model explains dark energy and an early ‘inflationary universe’ with a single scalar field which changes with time, with all masses increasing with the value of this field.
“It’s reminiscent of the Higgs boson recently discovered in Geneva. This elementary particle confirmed the physicists’ assumption that particle masses do indeed depend on field values and are therefore variable,” Wetterich said.
In his approach, all masses are proportional to the value of the so-called cosmon field, which increases in the course of cosmological evolution.
“The natural conclusion of this model is a picture of a universe that evolved very slowly from an extremely cold state, shrinking over extended periods of time instead of expanding,” Wetterich said.
Wetterich – who published his theory on arXiv – stresses that his theory does not render the Big Bang invalid – it’s just alternative.
“This is very useful for many practical predictions on the consequences that arise from this new theoretical approach,” Wetterich said. “However, describing the ‘birth’ of the universe without a singularity does offer a number of advantages. And in the new model, the nagging dilemma of ‘there must have been something before the Big Bang’ is no longer an issue.”
